We propose to continue the purification of acid ceramidase from human placenta. Acid ceramidase is the enzyme which is deficient in Farber's lipogranulomatosis. The effect of addition of purified enzyme will then be tested in cultured skin fibroblasts from patients with Farber's disease, and will conduct studies in experimental animals to test the possibility of enzyme replacement therapy. Other studies will be conducted with aggregate fetal rat brain cultures, which have been shown to form myelin. In this system, we will test the effects of various sulfated lipids on myelin stability, with the aim of improving our understanding of the pathogenesis of myelin breakdown in metachromatic leukodystrophy.